Cell division in rod-shaped bacteria
Cell division is a highly complex cytological process to produce viable progeny. Rod-shaped bacteria often divide with high precision at midcell to produce two equally sized daughter cells. In virtually all cells cytokinesis requires cytoskeletal elements. In bacteria the tubulin homolog FtsZ is the central cell division protein that assembles into a cytoskeletal scaffold known as the Z-ring. Subsequently, other proteins that drive invagination of cell membrane and synthesis of cell wall material are recruited to the division site. It has long been known that cell division in rod-shaped bacteria is restricted to midcell, between the segregated nucleoids.
In the last decades research has revealed that two inhibitory systems are involved in the spatial regulation of cytokinesis. The Min system has been shown to prevent aberrant cell division close to the cell poles, while nucleoid occlusion prevents cell division from occurring over the nucleoids. The current models suggest that the target of the inhibitory mechanism is the cytoskeletal element FtsZ and that the concerted action of nucleoid occlusion and Min are necessary for correct placement of the division machinery. However, recent advances show that at least the Min system also ensures that division occurs only once in a cell cycle and might also act downstream of FtsZ assembly. The combined action of these two negative regulators of FtsZ assembly defines the site of septation in many rod-shaped bacteria. Recent discoveries have added to the knowledge about the mechanism how the division machinery is spatially regulated and opened up new, unexpected, insights into division site selection.
Division site selection in rod-shaped bacteria. Curr Opin Microbiol. Oct 31 2009
Related:
- Unique cell division machinery in the Archaea
- Getting bacteria into shape
- Cell shape and cell-wall organization in Gram-negative bacteria
- Peptidoglycan – the strength and weakness of bacteria
Tags: Bacteria, Biology, division, Genetics, Microbiology, Science
